From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0b-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) by sourceware.org (Postfix) with ESMTPS id 4BE153858D32 for ; Thu, 1 Dec 2022 20:26:57 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 4BE153858D32 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=linux.ibm.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=linux.ibm.com Received: from pps.filterd (m0098417.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 2B1K1ct8010518; Thu, 1 Dec 2022 20:26:56 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=message-id : date : mime-version : subject : to : references : from : in-reply-to : content-type : content-transfer-encoding; s=pp1; bh=brkFWX0JcT4Ceb2f0UUrLv+/GId4DffGGLojAs3DeKk=; b=ana4cxoi0JFNPdWzFT80UUhlJqhir3Tylh8uGjFUqeGaz7DcYkfYbOD37fhIgV5CSLkb KQPptfTqhKmw4cPGPr4pdWvFQIZITYciXLsBiyIpCrgpb12nZ5tSIXbIpJ38S5TmOdKH IAUMtYavC52HCfEdHZ0V6i6MyWZ8AYvmjKui9rLu8vNne7oOKX/vOpz3FGSEUgnj58+Q 37T1VbteTd3nL8XZwbg/luDyIWocmX67Nc2RUtwPWN4vK6tFvwKJwLy4xmMdinIPexaR +e9uEGc/RqxO+aHtKAd5kfwHH8ktzyBlzhAbl5YkynxQOgydw4116aqRfXZ56cwlbjZF Tw== Received: from ppma03dal.us.ibm.com (b.bd.3ea9.ip4.static.sl-reverse.com [169.62.189.11]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 3m72xr0pvj-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 01 Dec 2022 20:26:56 +0000 Received: from pps.filterd (ppma03dal.us.ibm.com [127.0.0.1]) by ppma03dal.us.ibm.com (8.16.1.2/8.16.1.2) with SMTP id 2B1KJwOO001830; Thu, 1 Dec 2022 20:26:55 GMT Received: from smtprelay02.dal12v.mail.ibm.com ([9.208.130.97]) by ppma03dal.us.ibm.com with ESMTP id 3m3aea6cm3-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 01 Dec 2022 20:26:55 +0000 Received: from smtpav01.wdc07v.mail.ibm.com (smtpav01.wdc07v.mail.ibm.com [10.39.53.228]) by smtprelay02.dal12v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 2B1KQsWk20185692 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 1 Dec 2022 20:26:54 GMT Received: from smtpav01.wdc07v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 2F0F358063; Thu, 1 Dec 2022 20:26:54 +0000 (GMT) Received: from smtpav01.wdc07v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 5B7CE5804B; Thu, 1 Dec 2022 20:26:53 +0000 (GMT) Received: from [9.65.222.91] (unknown [9.65.222.91]) by smtpav01.wdc07v.mail.ibm.com (Postfix) with ESMTP; Thu, 1 Dec 2022 20:26:53 +0000 (GMT) Message-ID: <6bb448ff-c0e8-14c5-2621-000b8d3e20d3@linux.ibm.com> Date: Thu, 1 Dec 2022 14:26:52 -0600 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.4.1 Subject: Re: [PATCH] powerpc64: Remove old strncmp optimization Content-Language: en-US To: Adhemerval Zanella Netto , Rajalakshmi Srinivasaraghavan , libc-alpha@sourceware.org References: <20221129160257.1947346-1-rajis@linux.ibm.com> <8071be27-aebe-6f59-5929-ebf4807046c7@linux.ibm.com> <34bc5a63-b4a6-caac-4091-534982646577@linaro.org> From: Paul E Murphy In-Reply-To: <34bc5a63-b4a6-caac-4091-534982646577@linaro.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 X-Proofpoint-GUID: yTzpBTqatuJs3IXGhEKvjKEIzm4p4jPT X-Proofpoint-ORIG-GUID: yTzpBTqatuJs3IXGhEKvjKEIzm4p4jPT X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.219,Aquarius:18.0.923,Hydra:6.0.545,FMLib:17.11.122.1 definitions=2022-12-01_14,2022-12-01_01,2022-06-22_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 lowpriorityscore=0 malwarescore=0 mlxscore=0 priorityscore=1501 bulkscore=0 spamscore=0 adultscore=0 clxscore=1015 phishscore=0 suspectscore=0 impostorscore=0 mlxlogscore=968 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2210170000 definitions=main-2212010155 X-Spam-Status: No, score=-4.7 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_EF,NICE_REPLY_A,RCVD_IN_MSPIKE_H2,SPF_HELO_NONE,SPF_PASS,TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: On 11/30/22 7:49 AM, Adhemerval Zanella Netto wrote: > > > On 29/11/22 19:37, Paul E Murphy via Libc-alpha wrote: >> >> >> On 11/29/22 10:02 AM, Rajalakshmi Srinivasaraghavan via Libc-alpha wrote: >>> This patch removes the power4 strncmp optimization for powerpc64 and uses >>> __strncmp_ppc implementation instead.  Currently, both power4 and ppc >>> IFUNC variants result in similar performance. >> What cpu was used to test performance? I'd be curious if this holds for something like the venerable ppc970. > > > Do we really care, specially because I am not sure how it was evaluated on > power4 chip? On the merits of performance, I don't think this is sufficient justification. We should be more detailed. If the justification is tidying up, this patch is OK. That should be made explicit in the commit message. It does make me wonder, when is it OK to drop cpu specific optimizations? I suspect there aren't many running a modern BE ppc distro with P7 or older.